once players have secured an area, allow them to either a) stop zombies from spawning from building that are fortified B) reduce the amount of zombies from said buildings. you jsut locked down a clutch of buildings with wire and tanktraps but thos zed's keep spawning making it hard to do anything with the area thats in the safe zone. not to mention the TON of ammo you have to drop and buildings you cleared out a hundred times. also allow us to combine items to make things like the sandbag fortifications that are around, you see them at roadblocks and such.